This invention relates to a column which can be used in soil having a high water table. In particular it relates to a combination of column and pile for use in a sandy soil.
In sandy soils auger-cast piles have been used to carry foundation loads. In a typical situation, an hydraulic-powered auger with continuous flighting is rotated into the soil to a predetermined depth. A mixture of sand and cement is then pumped through a hole in the auger's stem while the auger is being slowly withdrawn from the hole. The resultant cementitious mixture is of greater density than the surrounding soil and thus acts to support the sides of the hole. This supporting action is especially useful in locations such as Florida where loose sands and a high water table make drill holes unsuitable. After the hole has been filled with cementitious material and the auger removed, steel reinforcement is inserted so that the final product is a steel reinforced concrete support column or pile cast within the soil with anchor bolts at the top to connect to the columns or post which it is intended to support.
In the past when a contractor attempted to use concrete posts or columns with auger-cast piles, considerable amounts of the cementitious grout were displaced when the post was inserted into the hole, sometimes as much as one-half the volume of the hole. Accordingly, this has not been a feasible method.